package org.apache.maven.model.management;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.inject.Named;
import javax.inject.Singleton;

import org.apache.maven.model.Dependency;
import org.apache.maven.model.DependencyManagement;
import org.apache.maven.model.Exclusion;
import org.apache.maven.model.Model;
import org.apache.maven.model.building.ModelBuildingRequest;
import org.apache.maven.model.building.ModelProblemCollector;
import org.apache.maven.model.merge.MavenModelMerger;

/**
 * Handles injection of dependency management into the model.
 *
 * @author Benjamin Bentmann
 */
@SuppressWarnings( { "checkstyle:methodname" } )
@Named
@Singleton
public class DefaultDependencyManagementInjector
    implements DependencyManagementInjector
{

    private ManagementModelMerger merger = new ManagementModelMerger();

    @Override
    public void injectManagement( Model model, ModelBuildingRequest request, ModelProblemCollector problems )
    {
        merger.mergeManagedDependencies( model );
    }

    /**
     * ManagementModelMerger
     */
    protected static class ManagementModelMerger
        extends MavenModelMerger
    {

        public void mergeManagedDependencies( Model model )
        {
            DependencyManagement dependencyManagement = model.getDependencyManagement();
            if ( dependencyManagement != null )
            {
                Map<Object, Dependency> dependencies = new HashMap<>();
                Map<Object, Object> context = Collections.emptyMap();

                for ( Dependency dependency : model.getDependencies() )
                {
                    Object key = getDependencyKey().apply( dependency );
                    dependencies.put( key, dependency );
                }

                for ( Dependency managedDependency : dependencyManagement.getDependencies() )
                {
                    Object key = getDependencyKey().apply( managedDependency );
                    Dependency dependency = dependencies.get( key );
                    if ( dependency != null )
                    {
                        mergeDependency( dependency, managedDependency, false, context );
                    }
                }
            }
        }

        @Override
        protected void mergeDependency_Optional( Dependency target, Dependency source, boolean sourceDominant,
                                                 Map<Object, Object> context )
        {
            // optional flag is not managed
        }

        @Override
        protected void mergeDependency_Exclusions( Dependency target, Dependency source, boolean sourceDominant,
                                                   Map<Object, Object> context )
        {
            List<Exclusion> tgt = target.getExclusions();
            if ( tgt.isEmpty() )
            {
                List<Exclusion> src = source.getExclusions();

                for ( Exclusion element : src )
                {
                    Exclusion clone = element.clone();
                    target.addExclusion( clone );
                }
            }
        }

    }

}
